This article was written by John Potter, VP/Training, Radio Advertising Bureau, and is one of the best I have seen on the subject:
http://www.rab.com/public/rst/article.cfm?article=1&id=1916&view=email
George
Media Services Group
Thoughts and observations on the radio/TV station and wireless tower trading markets. A look at the impact and integration of new media into station operations. Station values, stations for sale, radio and TV station news, towers, and more from a Director of Media Services Group and co-publisher of Inside Towers.